Important

Add GCPVertexGeminiSFTConfig to Python client OptimizationConfig and update tests and Rust deserialization to support it.

• Behavior:
  • Add GCPVertexGeminiSFTConfig to OptimizationConfig in __init__.py for visibility in Python client.
  • Update deserialize_optimization_config() in pyo3_helpers.rs to handle UninitializedGCPVertexGeminiSFTConfig.
• Tests:
  • Add test_sync_gcp_vertex_gemini_sft() and test_async_gcp_vertex_gemini_sft() in test_optimization.py for synchronous and asynchronous testing of GCPVertexGeminiSFTConfig.
  • Modify mixed_rendered_samples in conftest.py to adjust tool parameters structure.

^{This description was created by for 193a3a8. You can customize this summary. It will automatically update as commits are pushed.}